what does the CP251 sample and hold sound like?

[Keith collins]

another novice question:
what does the CP251 sample and hold actually do/sound like?

i don't own any moogs that have that function, but it sounds like it could be useful.

the sound clip on the moog site of the sample and hold doesn't sound like anything particular new to me. couldn't you get that sound with running a synth direct into an MF101?
thanks!

[eric coleridge]

Sample and hold can be used for modulation like LFOs are used, and the sound is similar. As you know, when you route an LFO to a Filter or Oscilator, those modules take on the sound of the LFO, be it square or triangle or whatever.
The archtypical sample and hold modulation sounds kind of like a combination of those two waves plus noise signal. It can sound like alternating waves or a jumble of waves and other things. You might have heard this sound as "the sound computers make while computing" (not in real life, but in science fiction movies and television). It's a sound typical of modular synths
This S+H circuit "samples" the voltage that you supply it for a variable amount of time and repeats by voltage control.
Alot of synths (like SH101) have a modulation source called "random" in addition to their LFO waves that randomly alternates between different LFO waves and Noise. This is for a pseudo S+H effect and sounds similar.
S+Hs are used in other places on synthesizers and aren't neccesarily a part of sound shaping, and for that reason, I think most all synths have S+H. But they don't all use it for modulation.
But, it's kind of cool, because it allows a synth to sort of play itself and freak out on it's own.

Alot of the Moogerfoogers seem to supply basic modular synth components that aren't presesnt on many of the older Moog synths. So, the CP251 supplies you with S+H (and a bunch of other syuff), the 101 give you an Envelope Follower, 102 Ring Mod, etc...
These are all really cool sound shaping circuits that you would never know if you've only played older Moogs. Other brands have different combinations these tools, very few synths, if any, have everything. The Arp Odyssey comes pretty close.

[Keith collins]

thank you!

[Robzilla]

Is there another way to get S+H, the CP is expensive..

[little doodler]

so can you run any sound source through a cp's sample & hold?

[chris allert]

one other thing worth mentioning about the cp251 sample and hold is that it's a very high quality circuit that's pre-patched in very useful ways. compared to other sample/hold circuits i've tried, the moog one holds the sampled voltage for a very long time while on other circuts the voltage begins to fall after a few seconds. on the cp251 there are two sample/hold outputs, one of them "smoothed out" meaning that the voltage gradually changes to the new sampled voltage on the smoothed output, and the amount of smoothnes is automatically tuned to the speed of the internal lfo that triggers the sampling. it's hard to explain here, but it's incredibly useful the way this thing is patched.

i wouldn't recommend trying to save money by going with another manufacturer. first, nobody else makes anything quite like the cp251, and second, to reproduce all it's features in a modular system, you'll probably spend more money and end up with something taking up much more space. to just get the noise -> sample/hold feature without smoothing, you can do this with just two modules on most systems. but the smoothed output is really cool, so you'll also need a module for this (called a "slew limiter" or "lag processor" or "portamento" depending on the system), and on most systems this module can't automatically track the sampling rate so you still won't reproduce this feature.

if you have two or more cp251s, one fun thing to do is patch the smoothed output of each into an attenuator and then into the lfo frequency input of the other. this gives you two wildly fluctuating control voltages that sort of follow each other's lead.

i have two of these, but i'd really like to have about 16 of them.

[asd]

so can you run any sound source through a cp's sample & hold?

there's an "in" jack for the sample and hold. I assume that you can use any sound source or lfo/control voltage as the source that is sampled (so you could get 'step' kind of sounds by sampling a sine/triangle/sawtooth wave as it rises and falls). I can't say for sure since I haven't had the chance to play around with one.



Chris, your post only makes me want a cp even more...

[chris allert]

so can you run any sound source through a cp's sample & hold?

there's an "in" jack for the sample and hold. I assume that you can use any sound source or lfo/control voltage as the source that is sampled (so you could get 'step' kind of sounds by sampling a sine/triangle/sawtooth wave as it rises and falls). I can't say for sure since I haven't had the chance to play around with one.



Chris, your post only makes me want a cp even more...

yes, although it's internally patched, patching something to either the "in" or the "trigger" input for the sample/hold will use that input instead of the internally patched one. one interesting thing about this is that if you patch something to the trigger input, the smoothing will still be tuned to the internal lfo speed, which is voltage controllable, opening up a lot of interesting possibilities.

[eric coleridge]

Is there another way to get S+H, the CP is expensive..

It seems expensive for a device that doesn't actually produce sound or even really modify sound (strictly speaking). But it's very relative, because (as others have described above) this little device performs the job of hundreds, if not, thousands of dollars of modular equipment. It's a voltage processing device and as such there really is no other product like it besides dedicated modules on a modular synth.

So, if your interested in getting started in modular synthesis, and you don't want to sell your car for a new modular system, it's the best place to start. Plus it's a real Moog and decended from components on the original modular synth.

Besides, I see them sell used on e-bay all the time for well under $300. Sometimes $200 even. Theres probably not a huge market for them, so they don't do so well on re-sale.

You can get Sample and Hold on lots of different vintage and modern synths for effecting internal sounds(Odysseys, Axxes, some Roland SHs, etc.).
In fact, all analog synths that we know and love are really just pre-wired, pre-patched mini-modulars and most all of them have the potential to be used for more than just sending sound to an amp. Some have jacks to allow some interaction, but most would need to be drastically modified for flexible extenal processing.

One exception to these others is the Micromoog, which is a really amazing little monosynth that excels in modulation options (but is usually considered lacking in overall sound and tone). It has a modulation output that allows you to send it's S+H to other synths. It doesn't have the same kind of flexability as the CP251 though.

Another synth that does have a similarly flexable S+H as the CP251 is the semi-modular Korg MS20. You get alot of synth with the MS20, but it's no secret, and you usually have to pay $1000 for all of it's flexability and sound shaping.

But if you have a CP251 and a few MoogerFoogers you have most of what you get in an MS20 (and in some ways more).

[GregAE]

another novice question:
what does the CP251 sample and hold actually do/sound like?

Keith -

Grab a copy of 'Power Tools for Synthesizer Programming' by Jim Aiken. It's a great book for EM novices (despite what you might think from the title). The book comes with a CD of sound examples that provide audio illustrations of waveforms, envelopes, filters and modulations - everything you need to understand how synthesis works.

- Greg

[hieronymous]

Here's a short clip showing one of the possible applications of sample and hold - it's similar to the sound that Frank Zappa used on "Ship Ahoy" from Shut Up 'n' Play Yer Guitar, Lather, etc.

The first sound in the clip below is clean bass, then bass through the MF-101 low pass filter, then a second bass enters with fuzz through the MF-101, and then you hear the frequency of the MF-101 being controlled by the sample and hold. I hope that makes sense!

fuzz filter frenzy

Remember, this is only one of the things that it can do. I've also used it to randomly control the amount of feedback on the MF-104...

[Rogue]

Thanks for the sound clip Hieronymous! I'm also a synth noob, still learning this stuff. I keep thinking that when I have more money, it's going towards more Moogerfoogers. I might just sell off my MG-1... I already can't wait to unload my SY-77...

I wish I had the money for a Voyager

[Keith collins]

okay, that clip totally helped. i've heard that effect before, i just never knew it was "sample and hold" i was hearing.

now i have to go buy one!

[eric coleridge]

Another good resource for understanding whats going on in your synths are the Moog synth manuals. They were mostly written by Tom Rhea who was a designer for Moog Music throughout the 70s. I found the Micromoog manual particularly helpful because the Micromoog has an "open system" made for interacting with other equipment (like Moogerfoogers). You can download it here (scroll down):

http://www.fantasyjackpalance.com/fjp/s ... omoog.html

I bought a Micro in 92' for $40 at a pawnshop and owned it for 10 years without ever realizing what all those jacks on the back were for. There weren't the internet resources available to me then that there are today and unfortunately I got rid of the Micro before I knew it's greater potential. I wish I still had it, especially now that manuals are so easy to come by.

One other informative site to check out is synthesizers.com
They sell relatively inexpensive modular synths based on Moog modular designs. They even look just like Moog modulars.